Fan unit

ABSTRACT

A fan main body includes a blade that rotates and a frame that rotatably supports the blade, and a casing including a main body with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess. The housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward. The snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion. A lower surface of the claw portion is inclined upward toward the tip of the claw portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of PCT Application No.PCT/JP2018/004224, filed on Feb. 7, 2018, and priority under 35 U.S.C. §119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No.2017-024095, filed Feb. 13, 2017; the entire disclosures of which areincorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to a fan unit.

2. BACKGROUND

A heat dissipation device (fan main body) may be attached to an electricdevice to dissipate heat generated internally to the outside. As afixing structure of such a heat dissipation device, one employing screwfixing is known (JP 2000-209717 A).

It is conceivable to reduce costs by adopting a snap fit as a fixingstructure of a heat dissipation device. However, in general, a fixingstructure using a snap fit has a problem that it is easily loosened andrattled.

SUMMARY

Example embodiments of the present disclosure provide fan assembliesthat each include a fixing structure that reduces costs and suppressesloosening and rattling.

One example embodiment of a fan assembly of the present disclosureincludes a fan main body including a blade that rotates and a frame thatrotatably supports the blade, and a casing including a main bodyprovided with a housing recess in which the fan main body is to behoused, and a snap-fit portion to fix the frame in the housing recess.The housing recess includes a housing bottom including a surface facingupward and a housing inner circumferential portion extending upward fromthe housing bottom, and opens upward. The snap-fit portion includes anelastic portion extending upward along the housing inner circumferentialportion, and a claw portion projecting horizontally from a tip endportion of the elastic portion. A lower surface of the claw portion isinclined upward toward the tip of the claw portion. The frame isinterposed between and in contact with the lower surface of the clawportion and the housing bottom.

According to one example embodiment of the present disclosure, it ispossible to provide a fan assembly including a fixing structure thatreduces costs and suppresses loosening and rattling.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the example embodiments with referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fan assembly of one example embodimentof the present disclosure.

FIG. 2 is a plan view of a fan assembly of one example embodiment of thepresent disclosure.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2.

FIG. 4 is a plan view of a casing of one example embodiment of thepresent disclosure.

FIG. 5 is a partial cross-sectional view taken along line V-V of FIG. 4.

FIG. 6 is a cross-sectional view for explaining a process of housing afan main body of one example embodiment of the present disclosure in ahousing recess.

FIG. 7 is a perspective view of a positioning pin provided to a housingbottom of one example embodiment of the present disclosure.

FIG. 8 is a cross-sectional view of a positioning hole inserted in apositioning hole of one example embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, a fan assembly 1 according to an example embodiment of thepresent disclosure will be described with reference to the accompanyingdrawings. In the accompanying drawings, an xyz coordinate system isshown appropriately as a three-dimensional orthogonal coordinate system.In the xyz coordinate system, a z-axis direction is assumed to be adirection parallel to a central axis J of a fan main body 5. A y-axisdirection is assumed to be a direction orthogonal to the z-axisdirection, extending from the upper right to the lower left in FIG. 1.An x-axis direction is assumed to be a direction orthogonal to both they-axis direction and the z-axis direction.

In the following description, the positive side (+z side, one side) inthe z-axis direction is referred to as an “upper side”, and the negativeside (−z side, the other side) in the z-axis direction is referred to asa “lower side”. It should be noted that the definitions of the upperside and the lower side are made simply for the sake of description, andare not meant to restrict actual relative positions or directions. Also,unless otherwise explained, a direction (z-axis direction) parallel tothe central axis J is simply referred to as an “axial direction” or a“vertical direction”, a radial direction having its center on thecentral axis J is simply referred to as a “radial direction”, and acircumferential direction having its center on the central axis J, thatis, a direction about the central axis J, is simply referred to as a“circumferential direction”.

<Fan Assembly>

FIG. 1 is a perspective view of a fan assembly 1 of the present exampleembodiment. FIG. 2 is a plan view of the fan assembly 1. FIG. 3 is across-sectional view taken along line of FIG. 2. The fan assembly 1includes two fan main bodies 5 and a casing 2 that houses the two fanmain bodies 5. The casing 2 is provided with housing recesses 30 openedto the upper side. The fan main body 5 is inserted into the housingrecess 30 of the casing 2 from the upper side, and is housed in thehousing recess 30.

[Fan Main Body]

The fan main body 5 has an impeller (blade portion) 50 that rotatesaround a central axis J extending in the vertical direction, a motor(not shown) that causes the impeller 50 to rotate, and a frame 55 thatsupports the impeller 50 and the motor.

The impeller 50 has a cylindrical impeller cup 50 a connected to therotation shaft of the motor along the central axis J, and a plurality ofwings 50 b arranged along the circumferential direction from the outerperipheral surface of the impeller cup 50 a. The impeller 50 rotates ina counterclockwise direction as viewed from above, for example. Themotor is disposed inside the impeller 50.

The frame 55 is in a form of a rectangular tube extending in thevertical direction. The outer shape of the frame 55 is substantiallysquare when viewed from the vertical direction. The frame 55circumferentially surrounds the impeller 50 and the motor from theradially outer side. The frame 55 rotatably supports the impeller 50.The frame 55 also supports the motor from below. The frame 55 has cornerportions 55 a arranged at the four corners. The corner portion 55 a issubstantially triangular when viewed from the vertical direction. Thecorner portion 55 a has a through hole 55 b. A screw for fixing theframe 55 to the casing 2 can be inserted into the through hole 55 b.Such a screw is used as a backup for a snap fit fixing structuredescribed later. That is, the frame 55 can be fixed to the casing 2 witha screw inserted into the through hole 55 b and fastened to the casing2, even if the fixing structure by the snap fit is damaged for anyreason.

The frame 55 has an upper surface 55 c facing upward and a lower surface55 d facing downward. The upper surface 55 c and the lower surface 55 dare provided with openings at least in a portion overlapping with theimpeller 50 when viewed from the vertical direction, so that the airflow accompanying the rotation of the impeller 50 is not hindered.

As viewed from the upper side, the edge of the frame 55 is provided withfour upper holding portions (first holding portions) 56. The upperholding portion 56 is in the form of a plate substantially parallel tothe upper surface 55 c. The upper holding portion 56 is located belowthe upper surface 55 c. The upper holding portion 56 is recesseddownward with respect to the upper surface 55 c. As shown in FIG. 3, theupper holding portion includes a first holding upper surface (uppersurface) 56 a facing upward, and a first holding lower surface (lowersurface) 56 b located on the opposite side of the first holding uppersurface 56 a. The four upper holding portions 56 are respectivelyprovided in pairs on two opposing sides of the four sides of the frame55, when viewed from above. A space is provided above the upper holdingportion 56. In the space above the upper holding portion 56, a clawportion 42 of the casing 2, described below, is housed.

As viewed from below, the edge of the frame 55 is provided with fourlower holding portions (second holding portions) 59 having the sameconfiguration as that of the upper holding portion 56. The lower holdingportion 59 is located above the lower surface 55 d and below the upperholding portion 56. The lower holding portion 59 is recessed upward withrespect to the lower surface 55 d. The lower holding portion 59 has ashape in which the upper holding portion 56 is vertically inverted. Thelower holding portion 59 overlaps with the upper holding portion asviewed from the vertical direction. The lower holding portion 59includes a second holding upper surface (upper surface) 59 a facingupward when the fan main body 5 is inverted, and a second holding lowersurface (inversion lower surface) 59 b located opposite to the secondholding upper surface 59 a. In FIG. 3, the second holding upper surface59 a faces downward, and the second holding lower surface 59 b facesupward.

According to the present example embodiment, the fan main body 5 has theupper holding portion 56 and the lower holding portion 59 which aredisposed at different positions in the vertical direction and overlapwith each other when viewed from the vertical direction. In the upperholding portion 56 and the lower holding portion 59, claw portions arehooked to either the upper holding portion 56 or the lower holdingportion 59 when the fan main body 5 is inverted. As a result, the fanmain body 5 can be housed in the housing recess 30 in an invertedmanner, and the air blowing direction to the casing 2 can be easilychanged.

As shown in FIG. 3, the lower surface 55 d of the frame 55 contacts thehousing bottom 31 in a state where the fan main body 5 is housed in thehousing recess 30. The lower surface 55 d has a positioning hole 57 intowhich a positioning pin 33 provided to the housing bottom 31 isinserted. Similarly, the upper surface 55 c of the frame 55 has apositioning hole 57A. In the positioning hole 57A, the positioning pin33 is inserted when the fan main body 5 is inverted and housed in thehousing recess 30.

[Casing]

FIG. 4 is a plan view of the casing 2. FIG. 5 is a cross-sectional viewtaken along line V-V of FIG. 4. As shown in FIG. 4, the casing 2 has amain body 3 provided with two housing recesses 30, and snap-fit portions4 provided four for each housing recess 30. The housing recess 30 housesthe fan main body 5 therein. The snap-fit portion 4 fixes the frame 55of the fan main body 5 in each of the housing recesses 30.

[Main Body 3]

The main body 3 has a rectangular shape in a plan view in which onedirection (in the present example embodiment, the y-axis direction) haslong sides 3 a and 3 b when viewed from the vertical direction. The mainbody 3 has a symmetrical shape with respect to a center line L passingthrough the center of the pair of long sides 3 a and 3 b when viewedfrom the vertical direction. The main body 3 has an upper surface 3 cfacing upward.

The housing recess 30 is recessed downward from the upper surface 3 c ofthe main body 3 and opens to the upper side. The two housing recesses 30are provided side by side in the direction in which the long sides 3 aand 3 b of the main body 3 extend. The housing recess 30 has asubstantially square shape as viewed from above. The housing recess 30has a housing bottom 31 having a bottom surface (a surface facingupward) 31 a, and a housing inner circumferential portion 32 extendingupward from the housing bottom 31.

The housing bottom 31 is substantially square when viewed from above.The housing bottom 31 has an opening 31 h penetrating in the verticaldirection. The opening 31 h of the housing bottom 31 overlaps with atleast the impeller 50 of the fan main body 5 when viewed from thevertical direction, and does not inhibit the air flow accompanying therotation of the impeller 50.

The bottom surface 31 a of the housing bottom 31 is provided withpositioning pins 33 for positioning the fan main body 5 in the housingbottom 31. The positioning pin 33 extends upward from the housing bottom31. The positioning pin 33 is to be inserted into a positioning hole 57provided in the frame 55.

The housing inner circumferential portion 32 surrounds the housingrecess 30 from the radially outer side (horizontal direction). Thehousing inner circumferential portion 32 extends upward in an angulartube shape from the outer edge of the bottom surface 31 a. As shown inFIG. 4, the housing inner circumferential portion 32 is provided withfour recesses 32 a that open to the upper side and to the inner side ofthe housing recess 30. Two of the four recesses 32 a, provided to onehousing recess 30, are provided along one long side 3 b of the main body3, and the other two are provided along the other long side 3 b. Asshown in FIG. 3, the recess 32 a extends downward from the upper surface3 c of the main body 3 up to the middle of the depth direction (verticaldirection) of the housing recess 30. The recess 32 a has a recessedbottom surface 32 b facing upward. The recessed bottom surface 32 b islocated between the bottom surface 31 a of the housing recess 30 and theupper surface 3 c of the main body 3 in the vertical direction.

[Snap-Fit Portion]

As shown in FIG. 5, the snap-fit portion 4 includes an elastic portion41 extending upward along the housing inner circumferential portion 32,a claw portion 42 projecting horizontally from the tip of the upper sidethe elastic portion 41 toward the inner side of the housing recess 30,and a grip portion 43 positioned above the claw portion 42 andprojecting upward.

The elastic portion 41 extends upward from the recessed bottom surface32 b of the recess 32 a. As shown in FIG. 4, the elastic portion 41 hasa rectangular shape having a long side in a direction in which the longsides 3 a and 3 b of the main body 3 extend, when viewed from thevertical direction. The elastic portion 41 is easily bent in a direction(X-axis direction) orthogonal to the extending direction of the longsides 3 a and 3 b of the main body 3. As shown in FIG. 5, the elasticportion 41 has a front surface 41 a facing the inside of the housingrecess 30. The elastic portion 41 is elastically deformed in a statewhere the fan main body 5 is housed in the housing recess 30, andapplies a stress of pressing the claw portion 42 to the first holdingupper surface 56 a of the fan main body 5.

The claw portion 42 is located at an upper end portion of the elasticportion 41. The claw portion 42 has a tip 42 t located inside thehousing recess 30. The claw portion 42 protrudes from the front surface41 a of the elastic portion 41 toward the tip 42 t. The claw portion 42also has a claw upper surface (upper surface) 42 b facing upward and aclaw lower surface (lower surface) 42 a located on the opposite sidethereof and facing downward.

In the process of housing the fan main body 5 in the housing recess 30,when the fan main body 5 is moved downward toward the housing recess 30,the first holding lower surface 56 b of the fan main body 5 slides onthe claw upper surface 42 b, and the elastic portion 41 bends and theclaw portion 42 moves to the outside of the housing recess 30.Furthermore, at the stage when the first holding upper surface 56 areaches below the claw lower surface 42 a, the claw portion 42 moves tothe inside of the housing recess 30, and the claw portion 42 is caughtby the upper holding portion 56.

The claw lower surface 42 a faces the bottom surface 31 a of the housingbottom 31 in a state where the fan main body 5 is not housed in thehousing recess 30. The claw lower surface 42 a inclines upward towardthe tip 42 t of the claw portion 42. As shown in FIG. 3, the claw lowersurface 42 a contacts the first holding upper surface 56 a of the upperholding portion 56 of the frame 55 of the fan main body 5.

In the conventional snap-fit structure, when the dimensions of theobject to be fixed by the snap-fit structure vary and become smaller, agap is generated between the parts engaged with each other. Therefore,the object fixed by the snap fit structure may rattle by the amount ofthe gap generated.

On the other hand, in the present example embodiment, the distance fromthe base end in the projecting direction of the claw lower surface 42 ato the bottom surface 31 a is smaller than the distance along thevertical direction between the first holding upper surface 56 a and thelower surface 55 d of the frame 55. Meanwhile, the distance along thevertical direction from the tip in the projecting direction of the clawthe lower surface 42 a to the bottom surface 31 a is larger than thedistance along the vertical direction between the first holding uppersurface 56 a and the lower surface 55 d of the frame 55. In the clawportion 42, the claw lower surface 42 a is inclined as described above.Since the claw lower surface 42 a of the claw portion is pressed to theinside of the housing recess 30 by the elasticity of the elastic portion41, even if the dimensions along the vertical direction of the firstholding upper surface 56 a and the lower surface 55 d of the frame 55vary, the claw lower surface 42 a contacts the first holding uppersurface 56 a at somewhere in the projecting direction. Thus, the frame55 can be vertically interposed between the claw lower surface 42 a andthe bottom surface 31 a, and a stress due to the elasticity of theelastic portion 41 can be applied. The frame 55 is interposed in a stateof being in contact with the claw lower surface 42 a and the housingbottom 31, and rattling of the frame 55 is suppressed.

As shown in FIG. 4, four snap-fit portions 4 are provided to each of thehousing recesses 30. Since the casing 2 of the present exampleembodiment is provided with two housing recesses 30, the casing 2 has atotal of eight snap-fit portions 4. The four snap-fit portions 4provided to one housing recess are classified into two first snap-fitportions 4A disposed along one long side 3 a of the main body 3 and twosecond snap-fit portions 4B arranged along the other long side 3 b. Thefirst snap-fit portions 4A and the second snap-fit portions 4B arepaired. The pair of first and second snap-fit portions 4A and 4B opposeeach other along a direction (X-axis direction) orthogonal to thedirection in which the long sides 3 a and 3 b of the main body 3 extend.The claw portions 42 of the pair of snap-fit portions (first and secondsnap-fit portions 4A and 4B) face each other. Since the claw lowersurface 42 a inclines upward toward the opposed claw portion 42,stresses in the opposite direction are applied to the fan main body 5from the claw lower surfaces 42 a of the pair of claw portions 42. Thatis, the claw portions 42 of the pair of snap-fit portions 4A and 4Bpress the frame 55 to the opposite side, whereby loosening and rattlingof the frame 55 can be suppressed.

According to the present example embodiment, it is possible to suppressloosening and rattling of the fan main body housed in the housing recess30, without using a fastening structure such as a screw. As a result,the number of components can be reduced, the assembly process can besimplified, and cost reduction can be realized.

In the snap-fit portion 4, the pair of claw portions 42 may notnecessarily be disposed to face each other. As an example, the snap-fitportion 4 may be disposed only on one long side 3 a of the pair of longsides 3 a and 3 b. In that case, the snap-fit portion 4 generates astress that presses the fan main body 5 against the housing innercircumferential portion 32 on the other long side 3 b of the housingrecess 30, thereby suppressing rattling of the fan main body 5.

The inclination angle θa (see FIG. 5) of the claw lower surface 42 awith respect to the horizontal plane is preferably larger than 0° andsmaller than 45°, and more preferably, 3° or larger and 9° or smaller.By setting the inclination angle θa to be larger than 0°, the clawportion 42 can press the frame 55 against the inside of the housingrecess 30 to achieve the above-described effect. Further, by setting theinclination angle to be 3° or larger, the stress that the claw portion42 presses the frame 55 against the inside of the housing recess 30 canbe sufficiently increased, and loosening and rattling of the frame 55can be suppressed more effectively. By setting the inclination angle θato be smaller than 45°, even in the case where an upward stress iscaused in the fan main body 5 in a state where the fan main body 5 ishoused in the housing recess 30, it is possible to suppress slidingbetween the claw lower surface 42 a and the first holding upper surface56 a, and to suppress detachment of the fan main body 5 from the housingrecess 30. Further, by setting the inclination angle θa to be 9° orsmaller, detachment of the fan main body 5 can be suppressed moreeffectively.

The claw upper surface 42 b is inclined downward toward the tip 42 t ofthe claw portion 42. FIG. 6 is a cross-sectional view for explaining theprocess of moving the fan main body 5 downward and housing it in thehousing recess 30. In the process of housing the fan main body 5 in thehousing recess 30, the first holding lower surface 56 b of the fan mainbody 5 slides on the claw upper surface 42 b. Since the claw uppersurface 42 b is inclined downward toward the tip of the claw portion 42,the elastic portion 41 is elastically deformed outward by the stress formoving the fan main body 5 downward, whereby the claw portion 42 can bemoved to the outside of the housing recess 30. As a result, the distancebetween the claw portions 42 of the pair of snap-fit portions 4A and 4Bis made wider than the width of the fan main body 5, and the fan mainbody 5 can be housed in the housing recess 30.

The claw upper surface 42 b is curved in a circular arc, and theinclination with respect to the projecting direction (−x direction inFIG. 5) of the claw portion 42 increases toward the tip 42 t of the clawportion 42. That is, the claw upper surface 42 b is inclined downwardwhile the inclination with respect to the projecting direction of theclaw portion 42 is increased toward the tip 42 t of the claw portion 42.

The inclination angle of the claw upper surface 42 b with respect to theprojecting direction of the claw portion 42 is referred to as an uppersurface inclination angle. When the upper surface inclination angleapproaches 90°, the ratio of the component force in the lateraldirection, of the force exerted from the first holding lower surface 56b to the claw upper surface 42 b, increases in the housing process ofthe fan main body 5. Accordingly, the elastic portion 41 can beelastically deformed with a small force. Therefore, although the fanmain body 5 can be housed in the housing recess 30 with a small force,the dimension along the vertical direction of the claw portion 42 isincreased.

In the present example embodiment, the claw upper surface 42 b is curvedand the inclination of the claw upper surface 42 b with respect to theprojecting direction of the claw portion 42 is increased and graduallyapproached to 90° toward the tip 42 t. As a result, the housingoperation of the fan main body 5 can be facilitated, and the dimensionof the claw portion 42 in the vertical direction can be sufficientlyreduced. In addition, according to the present example embodiment, sincethe claw upper surface 42 b has the above-described configuration, evenwhen the posture of the claw portion 42 is inclined to the outside ofthe housing recess 30 due to the elastic deformation of the elasticportion 41, the inclination angle of the claw upper surface 42 b issecured to enable smooth housing operation.

The grip portion 43 protrudes upward from the claw portion 42. Bygripping the grip portion 43, the operator can elastically deform theelastic portion 41 so as to move the claw portion 42 toward the outsideof the housing recess 30. As a result, the operator can release theengagement of the claw portion 42 with the upper holding portion 56 andtake out the fan main body 5 from the housing recess 30.

[Positioning Pin and Positioning Hole]

FIG. 7 is a perspective view of the positioning pin 33 provided to thehousing bottom 31. FIG. 8 is a cross-sectional view of the positioninghole 57 inserted in the positioning hole 57.

As shown in FIG. 7, the positioning pin 33 protrudes upward from thebottom surface 31 a of the housing bottom 31. The positioning pin 33 islocated inside the recess 33 h formed on the bottom surface 31 a of thehousing bottom 31. The recess 33 h is recessed downward. The outer shapeof the recess 33 h in the plan view is circular. When viewed from thevertical direction, the positioning pin 33 and the recess 33 h haveconcentric circular shapes.

The positioning pin 33 has a pin main body 34 extending in the verticaldirection along an axis O1 parallel to the vertical direction, and aplurality of ribs 35 provided to the outer peripheral surface of the pinmain body 34.

The pin main body 34 has a cylindrical portion 34 b and a taperedportion 34 a. That is, the positioning pin 33 has the cylindricalportion 34 b and the tapered portion 34 a. The cylindrical portion 34 bextends along the axis O1 about the axis O1. The diameter of thecylindrical portion 34 b is uniform. The tapered portion 34 a is locatedabove the cylindrical portion 34 b. In the tapered portion 34 a, thediameter of the positioning pin 33 decreases, from base end 33 b side ofthe positioning pin 33 toward the tip 34 t. Since the tapered portion 34a is provided, it facilitates insertion of the positioning pin 33 intothe positioning hole 57. That is, the operator can insert thepositioning pin 33 into the positioning hole 57 along the taperedportion 34 a only by moving the fan main body 5 downward toward thehousing bottom 31. Thereby, positioning can be realized easily.

As shown in FIG. 6, in the process of housing the fan main body 5 in thehousing recess 30, the first holding lower surface 56 b contacts theclaw upper surface 42 b. Thus, in a state where the first holding lowersurface 56 b and the claw upper surface 42 b are in contact with eachother, a distance D3 between the lower end of the positioning hole 57and the housing bottom 31 is smaller than a height d of the positioningpin 33. Therefore, the positioning pin 33 is inserted into thepositioning hole 57 before the first holding lower surface 56 b and theclaw upper surface 42 b contact each other in the process of moving thefan main body 5 downward and housing it in the housing recess 30. Thepositioning pin 33 can be inserted into the positioning hole 57 beforepressing the fan main body 5 downward to elastically deform the elasticportion 41 of the snap-fit portion 4. The operator does not have toalign the positioning pin 33 with the positioning hole 57 while pressingthe fan main body 5 downward. Here, the positional relationship in thevertical direction between the upper holding portion 56, the positioninghole 57, and the positioning pin 33 has been described. Such arelationship is also applied to the relationship between the lowerholding portion 59, the positioning hole 57A, and the positioning pin 33when the fan main body 5 is housed in the housing recess 30 in aninverted state. That is, in the state where the fan main body 5 isinverted and the fan main body 5 is moved downward to bring the secondholding lower surface 59 b into contact with the claw upper surface 42b, the distance between the lower end of the positioning hole 57A andthe housing bottom 31 is smaller than the height of the positioning pin33.

The plurality of ribs 35 project radially outward in the radialdirection of the axis O1 from the cylindrical portion 34 b of the pinmain body 34. Also, the ribs 35 extend along the axis O1. In the presentexample embodiment, the rib 35 has a prismatic shape elongated in thevertical direction. The rib 35 extends upward along the outer peripheralsurface of the cylindrical portion 34 b from the bottom surface of therecess 33 h. The plurality of ribs 35 are equally spaced along the axisO1. In the present example embodiment, four ribs 35 are provided atintervals of 90° around the axis O1 with respect to one pin main body34.

When the positioning pin 33 is inserted into the positioning hole 57,the plurality of ribs 35 contact the inner circumferential surface ofthe positioning hole 57. Therefore, the positioning pin 33 can bepress-fit into the positioning hole by elastically deforming the ribs 35inward in the radial direction. Thus, the position of the positioningpin 33 can be suppressed from being shifted with respect to thepositioning hole 57. Therefore, the fan main body 5 can be fixed in thehousing recess 30 with high positional accuracy without being displaced.Further, as shown in FIG. 7, in the rib 35 of the present exampleembodiment, the protruding height of the upper end portion decreasesfrom the lower side toward the upper side. Thereby, the easiness inpress-fitting the positioning pin 33 into the positioning hole 57 isenhanced.

When the positioning pin 33 is pressed into the positioning hole 57,part of the rib 35 that elastically deforms may be scraped off.According to the present example embodiment, since the recess 33 h isprovided, part of the scraped rib 35 falls into the recess 33 h.Therefore, the scraped rib 35 is not pinched between the lower surface55 d of the frame 55 of the fan main body 5 and the bottom surface 31 aof the housing recess 30, so that the fan main body 5 can be suppressedfrom rising from the bottom surface 31 a.

The present disclosure is not limited to the above-described exampleembodiment, and other configurations can be adopted. For example, thenumber of fan main bodies 5 attached to the casing 2 is not limited tothat described in the example embodiment. Moreover, the number ofsnap-fit portions 4 with respect to one housing recess 30 is not limitedto that described in the example embodiment. Further, in the case ofhaving a plurality of snap-fit portions, the claw lower surface 42 a ofat least one snap-fit portion 4 may be inclined. Further, the shape ofthe claw upper surface 42 b is not limited to that described in theexample embodiment. Moreover, although the case where the claw portion42 hooks on the upper holding portion 56 has been illustrated in theexample embodiment, it is also possible to employ a structure that ithooks on the upper surface 55 c of the frame 55. Further, theabove-described example embodiment employs the configuration in whichthe lower holding portion 59 is provided to the frame 55 so that the fanmain body 5 can be attached to the casing 2 even when the fan main body5 is inverted. However, it is possible to adopt a structure in which thelower holding portion 59 is not provided, and the fan main body 5 maynot be attached to the casing 2 when it is inverted. In that case, itcan suppress the case where the fan main body 5 is assembled while beinginverted.

The respective configurations can be appropriately combined within arange not inconsistent with each other.

While example embodiments of the present disclosure have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. The scope of the presentdisclosure, therefore, is to be determined solely by the followingclaims.

1-12. (canceled)
 13. A fan assembly comprising: a fan main body including a blade that rotates, and a frame that rotatably supports the blade; and a casing including a main body provided with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess; wherein the housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward; the snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion; a lower surface of the claw portion is inclined upward toward a tip of the claw portion; and the frame is interposed between and in contact with the lower surface of the claw portion and the housing bottom.
 14. The fan assembly according to claim 13, wherein the casing includes at least a pair of the snap-fit portions, and the claw portions of the pair of the snap-fit portions face each other.
 15. The fan assembly according to claim 13, wherein an upper surface of the claw portion is inclined downward and increasingly inclined with respect to a projecting direction of the claw portion toward the tip of the claw portion.
 16. The fan assembly according to claim 13, wherein the main body includes a positioning pin extending upward from the housing bottom, and the frame includes a positioning hole into which the positioning pin is inserted.
 17. The fan assembly according to claim 16, wherein the positioning pin includes a tapered portion in which a diameter of the positioning pin decreases from a base end side toward a tip.
 18. The fan assembly according to claim 17, wherein the fan main body includes a holding portion including an upper surface on which the lower surface of the claw portion contacts and hooks; a lower surface of the holding portion contacts the upper surface of the claw portion when the fan main body is housed in the housing recess; and in a state where the lower surface of the holding portion is in contact with the upper surface of the claw portion, a distance between a lower end of the positioning hole and the housing bottom is smaller than a height of the positioning pin.
 19. The fan assembly according to claim 16, wherein the positioning pin includes a pin main body extending in a vertical direction, and a plurality of ribs projecting from an outer peripheral surface of the pin main body and extending in the vertical direction.
 20. The fan assembly according to claim 13, wherein the fan main body includes a first holding portion and a second holding portion which are at different positions in a vertical direction and overlap with each other when viewed in the vertical direction, and the claw portion hooks on the first holding portion and the second holding portion respectively when the fan main body is inverted.
 21. The fan assembly according to claim 20, wherein the main body includes a positioning pin extending upward from the housing bottom, and each of an upper surface and a lower surface of the frame includes a positioning hole into which the positioning pin is inserted when the fan main body is inverted.
 22. The fan assembly according to claim 21, wherein the positioning pin includes a tapered portion in which a diameter of the positioning pin decreases from a base end side toward a tip.
 23. The fan assembly according to claim 22, wherein a lower surface of one of the first holding portion and the second holding portion contacts the upper surface of the claw portion when the fan main body is housed in the housing recess, and in a state where the lower surface is in contact with the upper surface of the claw portion, a distance between a lower end of the positioning hole and the housing bottom is smaller than a height of the positioning pin.
 24. The fan assembly according to claim 21, wherein the positioning pin includes a pin main body extending in a vertical direction, and a plurality of ribs projecting from an outer peripheral surface of the pin main body and extending in the vertical direction. 